共查询到20条相似文献，搜索用时 781 毫秒
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AIM: To study the inhibitory effect and its mechanisms of the extract of Oratosquilla oratoria (EOS) on the activity of telomerase in human nasopharyngeal carcinoma cell line CNE-2Z. METHODS: MTT assay was used to determine the effect of different doses of EOS on the proliferation of CNE-2Z cells. The activity of telomerase was analyzed by TRAP-ELISA. The mRNA expression of hTERT was determined by RT-PCR, and the protein expression of c-Myc was detected by Western blotting. RESULTS: EOS inhibited the proliferation of CNE-2Z cells in a dose-dependent manner (P<0.01). Telomerase activity was decreased, the mRNA expression of hTERT and c-Myc in CNE-2Z cells was also decreased (P<0.01) by the treatment of EOS. The correlation between the down-regulatory expression of hTERT mRNA and inhibitory expression of c-Myc protein (P<0.05) under the condition of EOS exposure was observed. CONCLUSION: EOS inhibits the proliferation of CNE-2Z cells by reducing the activity of telomerase, which is related with the inhibitory expression of hTERT mRNA caused by the decrease in c-Myc production. 相似文献
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AIM:To construct a recombinant retrovirus vector carrying hTERT for establishing UCBMSCs with hTERT (hTERT-MSCs) to overcome their limited life span and detecting whether telomerized UCBMSCs line maintained long-term self-renewal and differentiation capacity. METHODS:The whole cDNA was generated by PCR amplifications from the plasmid pEGFP-hTERT-C1. The hTERT segments were subcloned into pLNCX2. The target cells were infected with these retroviral particles. The stably transfected cells were selected by neomycin and expanded life span which were designated hTERT-MSCs was observed. The expression of hTERT in mRNA level was detected by RT-PCR and the telomerase activity was measured by TRAP (PCR)-ELISA assay. The hTERT-MSCs were induced with 5-azacytidine to cardiac muscle cells and the specific marker of myocardiocyte was detected. RESULTS:The constructed plasmids were digested with restriction endonucleases (BglⅡand NotⅠ). Two characteristic segments including 6.1 kb and 3.6 kb were obtained. The hTERT-MSCs expressed hTERT in mRNA level. The telomerase activity of hTERT-MSCs was positive. The growth kinetics of hTERT-MSCs was higher than those in UCBMSCs. The hTERT-MSCs were induced to myocardiocyte. CONCLUSION:The hTERT recombinant retrovirus vector has been successfully constructed. The hTERT gene activates the telomerase and prolongs the life-span of cells. No effect of hTERT gene on some type of differentiation potential of MSCs is present. 相似文献
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AIM: To investigate the effect of transfection of hTERT gene into human mesenchymal stem cells (MSCs) on their telomerase activity and life-span.METHODS: Human MSCs were transfected with a pEGFP-hTERT plasmid by liposome-mediated transfection. Then the hTERT mRNA expression in MSCs was detected by RT-PCR. The activity of telomerase in transfected MSCs was detected by PCR and ELISA. The telomerase-positive MSCs was cultured in vitro and induced into neuron-like cells with EGF and bFGF. Neuron-specific markers (NF-M, MAP2) were detected by RT-PCR.RESULTS: hTERT fragment was identified in the hTERT-transfeced cells but not in the untransfected human bone marrow MSCs. The untransfected human MSCs remained telomerase-negative but the hTERT-transfected cells showed robust telomerase activity. The telomerase-negative MSCs entered a nondividing state and senesced after about 20 to 25 passages. In test group, however, telomerase-positive MSCs to date had undergone 35 passages. RT-PCR analysis showed that telomerase-positive MSCs expressed neuron-specific markers, such as NF-M or MAP2 after induced with EGF and bFGF in vitro. CONCLUSION: Ectopic expression of the hTERT gene in human MSCs reconstitutes telomerase activity. The transfection of hTERT gene into human MSCs extends their replicative life span and maintains their multipotent differentiation capacity. 相似文献
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AIM: To clarify the effects of angiotensin-(1-7) on the calcification in rat vascular smooth muscle cells(VSMCs) and its signal transduction.METHODS: Calcification of cultured rat VSMCs was prepared by incubation of VSMCs with β-glycerophosphate.Calcification was confirmed by Von Kossa staining.The cells were treated with angiotensin-(1-7).The calcium content,alkaline phosphatases activity,osteocalcin and Cbfa1 mRNA expression were also measured.RESULTS: Angiotensin-(1-7) inhibited the increases of calcium content,alkaline phosphatases activity（P>0.05）,osteocalcin concentration and Cbfa1 mRNA expression in calcified VSMCs（P<0.05）,and the effects of angiotensin II on calcium content,alkaline phosphatases activity,osteocalcin concentration and Cbfa1 mRNA expression in calcified VSMCs were also inhibited （P<0.05）.Angiotensin-(1-7) increased cAMP concentration in calcified VSMCs（P<0.05）and selective PKA inhibitor blocked the effects of angiotensin-(1-7) on calcium content,alkaline phosphatases activity,osteocalcin concentration and Cbfa1 mRNA expression（P<0.05）.CONCLUSION: Angiotensin-(1-7) can inhibit beta-glycerophosphate-induced calcification in VSMCs through cAMP-PKA-Cbfa1 pathway and antagonize the effect of angiotensin II on calcification in VSMCs. 相似文献
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AIM: To investigate the characteristic of T-cell acute lymphocytic leukemia 1 (TAL1) gene expression in acute myeloid leukemia (AML) cell lines and in primary AML cells from de novo AML patients with different subtypes. METHODS: Real-time PCR was used to determine the expression of TAL1 mRNA in acute leukemia cell lines (Jurkat, CCRF-CEM, HL-60 and NB4 cell lines) and peripheral blood mononuclear cells from 47 newly diagnosed AML patients. Twelve healthy individuals were served as healthy control group. RESULTS: A significantly increased level in TAL1 mRNA was found in AML cell lines (HL-60 and NB4), T-cell acute lymphacytic leukemia (T-ALL) cell lines (Jurkat, CCRF-CEM) and primary AML cells compared with the healthy controls. Over-expression of TAL1 was found in all detected AML subtypes, the highest level of TAL-1 mRNA was found in AML-M1 and AML-M5 subtype (P<0.05). CONCLUSION: High expression of TAL1 in AML might influence the differentiation and proliferation of myeloid cells, further investigation needs to confirm whether it would be as a biomarker for pathogenesis of AML. 相似文献
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TONG Xiu-zhen ZOU Wai-yi BU Shan-shan WANG Yan-sheng LI Juan LUO Shao-kai CHEN Yun-xian 《园艺学报》2008,24(11):2171-2174
AIM: To investigate nucleostemin gene expression in bone marrow of acute leukemia and its clinical significance.METHODS: The expression of nucleostemin in 67 acute leukemia patients was detected by fluorescent quantitative polymerase chain reaction (FQ-PCR). The correlation between the expression level of nucleostemin gene and clinical significance was analyzed.RESULTS: Significantly higher expression levels of nucleostemin gene were detected in the initially-treated acute leukemia patients than those in normal control group and complete remission (CR) group by FQ-PCR (P<0.01). The expression level of nucleostemin gene in the cells from ALL was significantly lower than that of the cells in ANLL (P<0.05). No significant difference of nucleostemin expression in various differentiation stages (M2, M3, M4, M5) of ANLL was found (P>0.05). No significant association was observed between nucleostemin expression levels and age, sex, hepatauxe, splenomegaly, WBC count of acute leukemia patients by logistic analysis. The patients with positive expression of nucleostemin had significantly lower complete remission rate than those with negative expression (51.3% vs 83.3%, P<0.05). The nucleostemin expression level was significantly reduced during complete remission. Long-term follow-up of nucleostemin expression level showed that continuous or significant increase in nucleostemin expression in acute leukemia patients predicts refractoriness and impending relapse.CONCLUSION: Expression level of nucleostemin in acute leukemia patients is obviously higher than that in normal control. Nucleostemin can be a marker for evaluating therapy efficacy and monitoring minimal residual diseases (MRD) in leukemias. 相似文献
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AIM: To explore the influence of long non-coding RNA HOTAIR on the proliferation and apoptosis of acute lymphoblastic leukemia cells via the regulation of glucocorticoid receptor (GR).METHODS: The expression le-vels of HOTAIR and GR mRNA in human bone marrow stromal cell line HS-5 and human acute lymphoblastic leukemia cell lines MOLT-4, CCRF-CEM and CEM-C1 were examined by RT-qPCR. HOTAIR was knocked down by siRNA in acute lymphoblastic leukemia cells. CCK-8 assay was used to assess the cell viability, and the effect of si-HOTAIR on the proli-feration of CEM-C1 cells was evaluated by BrdU method. The effect of si-HOTAIR on apoptosis of CEM-C1 cells was examined by Hoechst 33342 staining and Caspase-Glo® 3/7 assay. Western blot was utilized to examine the protein level of GR.RESULTS: The expression level of HOTAIR in acute lymphoblastic leukemia cells was significantly increased as compared with normal human bone marrow stromal cells (P<0.01). The viability and proliferation of acute lymphoblastic cells was inhibited, the apoptosis was induced, and the anti-proliferation effect of dexamethasone on CEM-C1 cells was enhanced after knockdown of HOTAIR expression (P<0.01). The expression of GR was up-regulated at both mRNA and protein levels (P<0.01).CONCLUSION: Long non-coding RNA HOTAIR may modulate the viability, proliferation and apoptosis of acute lymphoblastic leukemia cells via a GR regulatory way. 相似文献
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AIM: To observe whether transfection of mammalian expression vector pEGFP containing the gene of B-cell specific moloney leukemia virus insertion site 1(BMI-1) could express in human cervix cancer cell line HeLa, and to detect its effect on HOX family expression and cell cycle.METHODS: pEGFP-BMI-1 was transfected into HeLa cells with Lipofectamine 2000. The expression of pEGFP-BMI-1 was determined by EGFP fluorescence and Western blotting. SYBR green I real-time RT-PCR was used to quantitate mRNA expression of P16INK4a, hTERT, HOXA9, HOXB4 and HOXC13. FACS analysis was used to detect the change of cell cycle.RESULTS: In HeLa cells transfected with pEGFP-BMI-1, the results of real-time RT-PCR showed that the mRNA expressions of P16INK4a, HOXA9 and HOXC13 were reduced to 9.2%, 10.9% and 69.7%, respectively, as compared to control HeLa cells (P<0.01). However, hTERT and HOXB4 mRNA expressions did not change significantly (P>0.05). FACS analysis showed a decrease from 65.68 % to 50.53% in G1 population and a significant increase from 27.17% to 39.59 % in S population after transfection (P<0.01).CONCLUSION: BMI-1 over-expression in HeLa cells down-regulates mRNA expressions of P16INK4a, HOXA9 and HOXC13, decreases G1 population and increases S population. Therefore, BMI-1 may be involved in carcinogenesis and cancer development. 相似文献
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AIM: To investigate the role of p38 mitogen-activated protein kinase (MAPK) in cyclic mechanical stretch induced the expression of high mobility group box 1 protein (HMGB1) in alveolar macrophages (AMs). METHODS: AMs were cultured and seeded at 1×108 cells/L in 6-well Bioflex cell culture plates. Subsequently, the cells were exposed to cyclic mechanical stretch at 20% (group B) elongation using Flexercell 4000T cell stretching unit. In group C, cells were pre-treated with SB203580 (40 μmol/L) for 2 h before mechanical stretch. Group A served as control. The expression of HMGB1 mRNA in alveolar macrophages was detected by RT-PCR. p38 MAPK activity and the expression of HMGB1 protein were measured by Western blotting analysis. RESULTS: The expression of HMGB1 mRNA and protein, and the activity of p38 MAPK in AMs were significantly increased in group B than those in group A (P<0.05). SB203580, an inhibitor of p38 MAPK, significantly inhibited the inducing effect of mechanical stretch (P<0.05). CONCLUSION: Mechanical stretch regulates the expression of HMGB1 mRNA and protein in alveolar macrophages by activating p38 MAPK signal pathway. 相似文献
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AIM: To study the role of Snail in the renal tubular epithelial-myofibroblast transdifferentiation and fibronectin synthesis mediated by activator protein-1. METHODS: The cultured HK2 cells were divided into three groups: normal glucose group (NG), high glucose group (HG) and activator protein-1 (AP-1) inhibited group (AG). Concentration of fibronectin into the culture media was determined by ELISA. The activity of activator protein-1 was assessed with electrophoretic mobility shift assay (EMSA). The protein of E-cadherin and vimentin was determined by immunocytochemistry. RT-PCR was used to detect the mRNA expression of vimentin and Snail. Western blotting was used to detect the protein expression of E-cadherin.RESULTS: Secreted FN level was significantly up-regulated by the stimulation of high glucose (P<0.05), but the level significantly decreased in AP-1 inhibited group than that in high glucose group (P<0.05). AP-1 binding activity was significantly stimulated by high glucose and the inhibitor of AP-1 inhibited high glucose induced AP-1 activation in HK-2. High glucose induced Snail mRNA expression, while the level significantly decreased in AP-1 inhibited group than that in high glucose group (P<0.05). Upon the stimulation with high glucose, the expression of E-cadherin protein decreased markedly (P<0.05), while the level was higher in AP-1 inhibited group than that in high glucose group (P<0.05). Cultured with high glucose, the expression of vimentin mRNA and protein significantly increased (P<0.05), but the level significantly decreased in AP-1 inhibited group than that in high glucose group (P<0.05). CONCLUSION: High glucose induces the expression of Snail through the activation of AP-1. The expression of Snail downregulates E-cadherin expression and induces transdifferentiation of renal tubular cells characterized by vimentin expression and fibronectin synthesis. 相似文献